As disclosed in U.S. Pat. No. 4,594,453 (Ranken et al.), it is known that (hydrocarbylthio)aromatic amines can be prepared by reacting an aromatic amine with a hydrocarbyl disulfide in the presence of a catalytic amount of a Lewis acid. The Lewis acid contaminant can be removed by diluting the product with an organic liquid such as toluene, washing with an aqueous acid or base, and then removing the diluent and water. However, this decontamination technique is bothersome, uneconomical, and apt to be particularly unsatisfactory when the amine is to be used in an application in which even small amounts of water cannot be tolerated.